1. Field of the Invention
This invention relates to a method of and an apparatus for attaching a light-shielding leader to a light-room loading photosensitive material roll.
2. Description of the Related Art
A photosensitive material in a continuous length is taken up around a core 2 having a pair of light-shielding flanges 2a spaced from each other by a distance substantially equal to the width of the photosensitive material as shown in FIG. 9 in a dark room, and the photosensitive material roll 1 thus obtained is mounted on a take-up shaft 4 as shown in FIG. 10. Then a light-shielding leader 3 substantially equal to the photosensitive material in width is bonded to the leading end portion 1a of the photosensitive material roll 1, for instance, by adhesive tape 5 and the core 2 is rotated, whereby the light-shielding leader 3 is wrapped around the photosensitive material roll 1 and a light-room loading photosensitive material roll is obtained.
There have been known techniques in which slitters are shifted while the web is running in order to change the size of the web as disclosed, for instance, in Japanese Unexamined Patent Publication No. 47(1972)-5795.
It is difficult to accurately align the light-shielding leader 3 having a width substantially equal to that of the photosensitive material roll 1 with the leading end portion 1a thereof. Accordingly the light-shielding leader 3 can be sometimes bonded to the leading end portion 1a out of alignment with the leading end portion 1a as shown in FIG. 10 and sometimes bonded to the leading end portion 1a at an angle to the leading end portion 1a as shown in FIG. 11, which results in improper positioning of the side edges of the light-shielding leader 3, which results in deterioration in light-shielding performance of the leader 3 and a product defective in light-shielding.
Further there has been a problem that many light-shielding leaders 3 having different widths must be prepared according to the widths of photosensitive material rolls 1.